Perceived usefulness is defined her as "the degree to which a person believes that using a particular system would enhance his or her job performance." This follow from the definition of the word useful: "capable of being used advantageously." Within an organizational context, people are generally reinforced for good performance by raises, promotions, bonuses,and other rewards.A system high in perceived usefulness, in turn, is one for which a uesr believes in the existence of a positive ues-performance relationship